93tihil

Hey everyone! I have a 2003 E500
Ive had this "problem" since not long after I bought that car in late march, when I press the brake pedal firm enough to stay still (not when braking lightly) there is this sound that comes on from under the hood for about 1,5 seconds that sounds like somekind of engine/pump noise, it comes even when I have the engine and ignition off and press the brake pedal.
The car brakes without problem but the noise is rather loud and bothers me, apart from the constant "brakes - visit workshop" theres no other errors, what could it be?
I checked the brake fluid and its about 3 millimeters above max, could that have something to do with it?
Thanks in advance

bbirdwell

SBC pump under the hood. Your car is brake-by-wire which is why it is so important to ensure the main and auxiliary batteries are always in tip-top condition.

SBC = Sensotronic Brake Control. It's the big device with pump and pressure accumulator located passenger side front of the engine compartment.

93tihil

So does that mean i have to check my batteries and if they're good i need to change the pump?

mtrevelino

When your SBC goes bad, your dash board will light up like a Christmas tree and you will have "VERY" limited braking.
If your car was ever at the dealer for brake work (bleeding), they should have reset the counter to something like 600k pedal pushes. After the limit is reached, you will get the dash board lighting up.
Mike T.

bbirdwell

93tihil, PM me your email address and I'll send you some tech info on it. It'll help set your mind at ease.

Multiple actions activate the SBC pump; door opening, parking brake, turning on ignition key, unlocking the car with the key fob, depressing the brake pedal. It's a pretty noisy pump.

ot1

06 e320 115k, my SBC pump is very quiet, unnoticable, hums at most.